Helps ensure that the total pressure does not exceed the capacity of the air handling unit (AHU).
By accurately sizing fans, you prevent over-pressurizing the system, which wastes energy.
Specifically identifying if it's a 90-degree elbow, a tee, or a reducing transition. Why You Should Use One
I can help walk you through the calculation or direct you to a specific tool. Duct Pressure Loss Calculator | Plastec Ventilation
Proper sizing prevents noisy systems and ensures adequate air delivery to rooms.